Guanidinoacetic acid supplementation improves intestinal morphology, mucosal barrier function of broilers subjected to chronic heat stress

Abstract

The current study is designed to investigate dietary guanidinoacetic acid (GAA) supplementation on the growth performance, intestinal histomorphology, and jejunum mucosal barrier function of broilers that subjected to chronic heat stress (HS). A total of 192 male broilers (28-d-old) were randomly allocated to four groups. A chronic HS model (at a temperature of 32 °C and 50 to 60% relative humidity for 24 h daily) was applied in the experiment. Normal control (NC, ad libitum feeding, 22°C), heat stress group (HS, ad libitum feeding, 32°C), pair-fed group (PF, received food equivalent to that consumed by the HS group on the previous day, 22°C), guanidinoacetic acid group (HG, ad libitum feeding, supplementing the basal diet with 0.6 g/kg GAA, 32°C). The experiment was lasted from 28 to 35 and 28 to 42 of age of broilers. Our results showed that broilers subjected to HS had lower average daily feed intake and average daily gain (P < 0.05), higher feed-to-gain ratio and relative length of the small intestine (P < 0.05), as well as lower relative weight and weight per unit length of the small intestine (P < 0.05). HS damaged the small intestinal histomorphology by decreasing the small intestinal VH and the VH/CD (P < 0.05). Compared with the HS group, supplementation with 0.6 g/kg GAA increased jejunal VH and VH/CD (P < 0.05), but decreased relative weight and relative length of the small intestine (P < 0.05). Moreover, in comparison with NC, HS elevated intestinal permeability (D-Lactic acid concentration and diamine oxidase activity) and mRNA expression levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α (P < 0.05), reduced jejunal mucus thickness, number of goblet cells, IgA + cell density, and mucin2 mRNA expression level of broilers (P < 0.05). Compared with the HS group, dietary GAA elevated jejunal mucus thickness, goblet cell number and IgA + cell density (P < 0.05), and up-regulated jejunal mRNA expression of interleukin-1β and tumor necrosis factor-α (P < 0.05). In conclusion, heat stress impaired growth performance, and the intestinal mucosal barrier function of broilers. Dietary supplementation with 0.6 g/kg GAA alleviated heat stress-induced histomorphology changes of small intestine and jejunal mucosal barrier dysfunction.

Dietary Guanidine Acetic Acid Improves Ruminal Antioxidant Capacity and Alters Rumen Fermentation and Microflora in Rapid-Growing Lambs

“…This was consistent with the finding that AGAT can be feedback-inhibited by GAA [ 37 ]. Most metabolic studies on GAA have focused on the liver, blood, urea, and small intestinal segment mucosa [ 8 , 36 , 38 ]. The addition of GAA increased the rumen GAA content at both stages 1 and 2, confirming that GAA was degraded in the rumen and significantly correlated with the degradation rate (UGAA, 50.9%; CGAA, 15.8%).…”

An Assessment of the Effects of Guanidinoacetic Acid on the Performance and Immune Response of Laying Hens Fed Diets with Three Levels of Metabolizable Energy

“…In the present study, the ME level did not modify the morphological characteristics of the duodenum. However, GAA supplementation increased the width of the villi and the depth of the crypts and decreased the height of the villi, which is contrary to what was reported by Peng et al in 2003, in which an improvement in intestinal morphology was observed in broilers subjected to heat stress supplemented with 0.6 g/kg of GAA [ 36 ]. It has been shown that the length of the villi improves the absorption capacity of nutrients in the intestine and that deep crypts indicate high metabolic activity in the tissue, so modifications in these characteristics may indicate a reduction in the absorption of nutrients [ 37 , 38 , 39 ].…”

Heat stress exposure cause alterations in intestinal microbiota, transcriptome, and metabolome of broilers

“…Growth performance is an important indicator for evaluating whether the production efficiency of poultry meets people’s expectations. The decrease in growth performance caused by heat stress is related to decreased food intake ( Peng et al, 2023 ). The result of this study indicated that heat stress reduced the weight and ADG of broilers but had no effect on ADFI and FCR.…”